daemon, interfaces, travis: workaround build ID with Go 1.9, use 1.9 for travis tests

.travis.yml

@@ -4,9 +4,9 @@ git:
 jobs:
   include:
     - stage: quick
-      name: go 1.10/xenial static and unit test suites
+      name: go 1.9/xenial static and unit test suites
       dist: xenial
-      go: "1.10.x"
+      go: "1.9.x"
       before_install:
         - sudo apt --quiet -o Dpkg::Progress-Fancy=false update
       install:

daemon/api_test.go

@@ -1031,8 +1031,9 @@ func (s *apiSuite) TestSysInfo(c *check.C) {
 	// reload dirs for release info to have effect
 	dirs.SetRootDir(dirs.GlobalRootDir)
 
-	buildID, err := osutil.MyBuildID()
-	c.Assert(err, check.IsNil)
+	buildID := "this-is-my-build-id"
+	restore = MockBuildID(buildID)
+	defer restore()
 
 	sysInfoCmd.GET(sysInfoCmd, nil, nil).ServeHTTP(rec, nil)
 	c.Check(rec.Code, check.Equals, 200)
@@ -1101,8 +1102,9 @@ func (s *apiSuite) TestSysInfoLegacyRefresh(c *check.C) {
 	})
 	c.Assert(err, check.IsNil)
 
-	buildID, err := osutil.MyBuildID()
-	c.Assert(err, check.IsNil)
+	buildID := "this-is-my-build-id"
+	restore = MockBuildID(buildID)
+	defer restore()
 
 	sysInfoCmd.GET(sysInfoCmd, nil, nil).ServeHTTP(rec, nil)
 	c.Check(rec.Code, check.Equals, 200)

daemon/export_test.go

@@ -41,3 +41,11 @@ func MockMuxVars(vars func(*http.Request) map[string]string) (restore func()) {
 		muxVars = old
 	}
 }
+
+func MockBuildID(mock string) (restore func()) {
+	old := buildID
+	buildID = mock
+	return func() {
+		buildID = old
+	}
+}

interfaces/export_test.go

@@ -51,3 +51,11 @@ func MockIsHomeUsingNFS(new func() (bool, error)) (restore func()) {
 		isHomeUsingNFS = old
 	}
 }
+
+func MockReadBuildID(mock func(p string) (string, error)) (restore func()) {
+	old := readBuildID
+	readBuildID = mock
+	return func() {
+		readBuildID = old
+	}
+}

interfaces/system_key.go

@@ -80,6 +80,8 @@ var (
 	mockedSystemKey *systemKey
 
 	seccompCompilerVersionInfo = seccompCompilerVersionInfoImpl
+
+	readBuildID = osutil.ReadBuildID
 )
 
 func seccompCompilerVersionInfoImpl(path string) (string, error) {
@@ -103,7 +105,7 @@ func generateSystemKey() (*systemKey, error) {
 	if err != nil {
 		return nil, err
 	}
-	buildID, err := osutil.ReadBuildID(snapdPath)
+	buildID, err := readBuildID(snapdPath)
 	if err != nil && !os.IsNotExist(err) {
 		return nil, err
 	}

interfaces/system_key_test.go

@@ -60,9 +60,7 @@ func (s *systemKeySuite) SetUpTest(c *C) {
 	c.Assert(err, IsNil)
 
 	s.apparmorFeatures = filepath.Join(s.tmp, "/sys/kernel/security/apparmor/features")
-	id, err := osutil.MyBuildID()
-	c.Assert(err, IsNil)
-	s.buildID = id
+	s.buildID = "this-is-my-build-id"
 
 	s.seccompCompilerVersion = "123 2.3.3 abcdef123 -"
 	testutil.MockCommand(c, filepath.Join(dirs.DistroLibExecDir, "snap-seccomp"), fmt.Sprintf(`
@@ -83,6 +81,12 @@ func (s *systemKeySuite) testInterfaceWriteSystemKey(c *C, nfsHome bool) {
 	restore := interfaces.MockIsHomeUsingNFS(func() (bool, error) { return nfsHome, nil })
 	defer restore()
 
+	restore = interfaces.MockReadBuildID(func(p string) (string, error) {
+		c.Assert(p, Equals, filepath.Join(dirs.DistroLibExecDir, "snapd"))
+		return s.buildID, nil
+	})
+	defer restore()
+
 	err := interfaces.WriteSystemKey()
 	c.Assert(err, IsNil)
 
@@ -104,9 +108,6 @@ func (s *systemKeySuite) testInterfaceWriteSystemKey(c *C, nfsHome bool) {
 	seccompActionsStr, err := json.Marshal(release.SecCompActions())
 	c.Assert(err, IsNil)
 
-	buildID, err := osutil.ReadBuildID("/proc/self/exe")
-	c.Assert(err, IsNil)
-
 	compiler, err := seccomp_compiler.New(func(name string) (string, error) {
 		return filepath.Join(dirs.DistroLibExecDir, "snap-seccomp"), nil
 	})
@@ -117,7 +118,7 @@ func (s *systemKeySuite) testInterfaceWriteSystemKey(c *C, nfsHome bool) {
 
 	overlayRoot, err := osutil.IsRootWritableOverlay()
 	c.Assert(err, IsNil)
-	c.Check(string(systemKey), Equals, fmt.Sprintf(`{"version":1,"build-id":"%s","apparmor-features":%s,"apparmor-parser-mtime":%s,"apparmor-parser-features":%s,"nfs-home":%v,"overlay-root":%q,"seccomp-features":%s,"seccomp-compiler-version":"%s"}`, buildID, apparmorFeaturesStr, apparmorParserMtime, apparmorParserFeaturesStr, nfsHome, overlayRoot, seccompActionsStr, seccompCompilerVersion))
+	c.Check(string(systemKey), Equals, fmt.Sprintf(`{"version":1,"build-id":"%s","apparmor-features":%s,"apparmor-parser-mtime":%s,"apparmor-parser-features":%s,"nfs-home":%v,"overlay-root":%q,"seccomp-features":%s,"seccomp-compiler-version":"%s"}`, s.buildID, apparmorFeaturesStr, apparmorParserMtime, apparmorParserFeaturesStr, nfsHome, overlayRoot, seccompActionsStr, seccompCompilerVersion))
 }
 
 func (s *systemKeySuite) TestInterfaceWriteSystemKeyNoNFS(c *C) {
@@ -128,6 +129,20 @@ func (s *systemKeySuite) TestInterfaceWriteSystemKeyWithNFS(c *C) {
 	s.testInterfaceWriteSystemKey(c, true)
 }
 
+func (s *systemKeySuite) TestInterfaceWriteSystemKeyErrorOnBuildID(c *C) {
+	restore := interfaces.MockIsHomeUsingNFS(func() (bool, error) { return false, nil })
+	defer restore()
+
+	restore = interfaces.MockReadBuildID(func(p string) (string, error) {
+		c.Assert(p, Equals, filepath.Join(dirs.DistroLibExecDir, "snapd"))
+		return "", fmt.Errorf("no build ID for you")
+	})
+	defer restore()
+
+	err := interfaces.WriteSystemKey()
+	c.Assert(err, ErrorMatches, "no build ID for you")
+}
+
 func (s *systemKeySuite) TestInterfaceSystemKeyMismatchHappy(c *C) {
 	s.AddCleanup(interfaces.MockSystemKey(`
 {